The overall objective is to integrate high quality meteorological, climatological, toxicological, microbiological, and air and water quality data, to rigorous human health outcome studies, for the purposes of economic cost-benefit analyses in Quito, Ecuador. Current empirical and observational evidence, coupled with the basic economic theories of externalities and public goods, suggest that public policy intervention is required to manage increasingly severe urban air and water quality conditions in Quito. The necessary data to design, implement, and evaluate appropriate and effective public policies, however, is incomplete or entirely lacking. If funded, the work outlined in this planning grant attempts to begin to collect the required data, and lays the foundation for numerous health, environment, and economic hypotheses. As an intrinsic and core part of laying this foundation, the outlined work provides substantial capacity building so that Ecuadorian agencies and authorities can continue to collect and analyze these types of data in the future, and indeed can ask and answer new questions as they arise in a changing economic, institutional, and environmental setting. The four specific aims are: 1) establish a set of pilot human health outcome studies, 2) establish a network of environmental exposure monitoring and analysis, 3) obtain economic data that will provide the basis for comparative risk assessments, risk benefit analyses, and address the cost effectiveness of potential public health policy changes, and 4) build research capacity in all three of the above arenas. To accomplish these aims an interdisciplinary team has been assembled, which builds upon a highly experienced community-based health research team, adding environmental scientists, statisticians, toxicologists, economists, and environmental policy experts. At the institutional level in Ecuador our team includes members of the Ministry of Public Health, key meteorological and air pollution monitoring institutions, the water authority of Quito, and an academic department of mathematics.